Dry printing and developing machine



March 18, 1952 F. o. TRUMP DRY PRINTING AND DEVELOPING MACHINE Filed Oct. 5, 1947 v INVENTOR. Frederick O. Trump Patented Mar. 18, 1952 2,589,748 I C E DRY PRINTING AND DEVELOPING MACHINE Frederick Otto Trump, Binghamton, N. Y., as-

signor to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware Application October 3, 1947, Serial No. 777,653

Claims.

This invention relates to dry printing and developing machines, and more specifically to .a.

- It is a general object of the invention to va-.

porize ammonia or other developing liquids in a chamber so arranged and so constructed that without permitting condensation to reach the sensitized surface of the developed material, the vapors actually employed for development shall be taken from the lowermost part of the chamber where they are of higher humidity and, therefore, adapted to accelerate the developing action.

Among the specific objects of the invention is that of devising a dry printing and/or developing machine in which the developer vaporizing chamher is so disposed that the perforations or openings through which the developing vapors pass to the sensitized material are located at the lower part of the chamber so that as the vapors are exuded through the said perforations they move with a substantial component of motion in a downward direction. v

Another object of the invention is that of devising a printing and developing machine of the type described in which the relative arrangement of parts is such that very little vertical height is taken up by the combined mechanism so that while the level at which introduction of material occurs is retained at a convenient height and the material travels through an extended pathway, the point of discharge of the printed and developed material substantially lower than in machines heretofore available.

It is another object of the invention to lower the overall height of the machine while retaining the functions of automatic separation of the originals after printing and stacking said originails in order of discharge thereof.

Another object of the invention is that of (16-.

vising a dry type printing and developing machine wherein the material to be printed and the sensitized material are fed at the front of the machine a more convenient location than that heretofore practiced.

Another object of the invention is that of devising a machine for printing and developing with ammonia. vapors in which the separation of the original from the sensitized sheet takes place when both are travelling in a direction not far removed from the horizontal thereby to take advantage of the effect-of gravity in separating the original in addition to other forces applied thereto.

Another object of the invention is that of devising a dev ping tank or machine of the type described hlcn shall function in what may be termed an inverted position, that is, with the perforated wall of the tank at or adjacent its lower portion. n addition to providing for exuding the vapors from the lower wall of the tank and in a general downward direction, it is a further object of the invention to provide for confining the condensation between the tank perforations and to conduct it to an adjacent part of the chamber.

It is another object of the invention to provide for vaporizing developer liquids within the inverted tank and for minimizing condensation by generally maintaining the temperature of the vapors above the dew point.

Other objects of the invention will become apparent from the following more detailed description.

In dry printing and developing machines, it has heretofore been the practice to pass an original and a sensitized sheet about a rotating cylinder at which printing takes place whereupon the original is separated from the printed sensitized sheet and passes on and upwardly toward a developing section of the machine. Due to the fact that the developing portion of such machines has always employed a vaporizing chamber at the top or, at least at a surface inclined toward the top and from which the developing vapors move in a generally upward direction, considerable height has been necessary to house the developing portion of the machine. Furthermore, the arrangement of parts according to the prior art has been such that movement of the original and sensitized I developing action at a relatively low part of the machine and to carry that action on for an extended distance horizontally or substantially horizontally of the machine without resort to relatively great increases in height as has previously been done especially where higher speeds of printing have made necessary the extension of the developer surface in order to secure adequate action of the vapors. While providing for automatic separation of originals after printing, and for st. ing them at the front of the machine, the total height is kept at a minimum. The prints are also discharged from the developer zone at the back of the machine so that fumes therefrom are kept away from the front of the apparatus.

In order to speed up the developing of the --printed sensitized material, advantage is taken of the fact that the more moist or more humid vapors have a more rapid action on vform a reservoir for condensation through which it may passto a lower part of the tank from which it is drained. To prevent condensation passing directly to the sensitized material and to guide it in a pathway so that it must eventually be discharged from the chamber, the perforations are extruded in a direction inwardly of the tank or are otherwise provided with inwardly 7 turned and upwardly directed rims or flanges, the

details of which will be described in following parts of the disclosure.

In combination with the above-mentioned changes in the vaporizing and developing parts of the apparatus, the printing section of the machine is so constructed that the printing cylinder and lamp are arranged adjacent the back of the machine with the feeding board extending conveniently toward the front of the machine thereby providing a substantial space above the feeding board for discharge of the original which may be received and rolled, or may be stacked in orderly sequence. By employment of a horizontally arranged vaporizing chamber and since the starting point for developing is relatively close to the front of the machine, the release of the material from the printing cylinder and separation of the original from the sensitized material is permitted to take place when they are moving in a direction not far removed from the horizontal. When an attempt is made to separate the original from the printed sensitized sheet, there is a tendency for the two to stick together and if the I: therefore, it is not necessary to employ as strong suction devices or other positive action as has heretofore been considered essential.

Both the original and sensitized material are removed from the printing cylinder by a jet of compressed air and then the sensitized-material is subjected to action of suction by which it is carried forwardly of the machine and slightly upwardly to be entered between positive guiding means from which it cannot escape and by which it is moved into contact with the sealing sleeve and tank surface or other supplementary surface functioning between the tank and sealing sleeve.

" Suction means is employed to draw the original downwardly away from the printed sensitized 'sheet, but that suction means merely supplements the natural force of gravity which is ever present to effect a separation at that point. After passing the suction means, the original is discharged into a tray or other receiving device at the front of the machine and conveniently located so that the operator may reprint or otherwise'dispose of it. 4

The invention will hereinafter be described by reference to one specific embodiment thereof illustrated in the accompanying figures of drawing, wherein:

Fig. 1 is a section taken through a dry developing machine to which the invention has been applied.

Fig. 2 is a section through a portion of the developing tray showing details of the perforated at a convenient height.

operative mechanism includes the printing deportion thereof, the sealing sleeve and sensitized material retained between these two elements.

Now referring to Fig. 1, the machine is shown in cross-section and includes, among other parts,

an outer casing H) which extends downwardly farther than indicated here to be supported on the floor so that the feedboard H is positioned The lower part of the vices and means for separating the original from the sensitized material which is fed on upwardly to be developed at the upper section of the machine. This printing mechanism comprises a cylinder 12 of transparent material such as heat resistant glass adapted to transmit that band of the ultraviolet portion of the spectrum for which the diazo-coated material is primarily sensitized. This cylinder is mounted for rotation and contains at its interior or central portion a lamp preferably of high pressure mercury vapor type similar to that described in United States Patent No. 2,308,130.

For guiding the sensitized material to and I about the printing cylinder, a plurality of tapes [3 are positively driven and pass about a series of guide rollers 54, I5, [5, and IT in such manner that the sensitized sheets, one of which is indicated at S, are gripped as they are advanced from the feed table ll by a series of tapes 18 passing about a plate l9 and. positively driven by a roller 20. The sensitized material is fed in registry with an original or tracing T both of which pass about cylinder I2 so that the sensitized material is subjected to the light and printed, whereupon both are separated from the cylinder I2 by a jet of air from the pressure chamber 2!. As these sheets pass above the chamber 2| and beneath the roller I! after separation from the cylinder, they are immediately caused to take different pathways as illustrated.

A suction chamber 22 has a series of apertures at its longest flat side which is disposed at an angle projecting slightly upwardly from the hori zontal. The suction exerted affects the printed sheet or sensitized material through cooperating perforations in the tapes. The suction exerted through the tapes and by suction chamber 22 is sufiicient to maintain all types of sensitized material in contact with the tapes it until the leading end of that material has entered between the guide elements 23 and 24 by which it is positively directed through a channel especially designed to cause the leading end of the sensitized sheet to enter and be controlled by the developing mechanism.

A second suction chamber 25 exerts a pulling force on the original T so that it is separated from the sensitized material and caused to be delivered into the receiving tray 25. The original material tends to fall away from the sensitized sheet due to the nearly horizontal arrangement of the parts and thus the suction exerted by the chamber 25 need not be as great as that exerted by chamber 22. This is a definite improvement over mechanism previously employed where the movement of the material in a nearly :vertical direction has necessitated considerably more suction for the original than for the sensitized sheets.

In this event, there has sometimes been about as much tendency to pull the leading edge of the sensitized sheet away from the suction chamber 22 as there has been to carry it along upwardly in the direction of the developer mechanism. With the present mechanism, the suction required for the originals is only about one-half that necessary for the sensitized material. The originals do not have to be flexed at the point of discharge.

After separation at the suction slot 25, the original passes over a rubber covered, driver roller 25 to be stacked in a tray 26 hinged at its inner end to occupy different positions nearer or farther from the horizontal in accordance with the size and type of material being printed. For this purpose, a plurality of apertures 21 are adapted to receive latching plungers at the outer end of the tray so as to make possible a plurality of. angular positions therefor.

The upper or developing portion of the mechanism includes among other elements a tank or vaporizing chamber generally indicated by 1111- meral 28 and which has therein a vaporizing tray 29 into which a solution of aqueous ammonia is fed at a proper rate and within which the ammonia is vaporized by application of heat prefer-- ably by a heater coil or rod 30. The vaporized ammonia occupies virtually the entire interior of the tank 28, and if desired, additional heating elements 30 may be employed to prevent condensation of the developer and to keep the vapors at substantially the same temperature throughout the interior of the chamber.

A sealing sleeve SI of a suitable rubber compound preferably resistant to the action of ammonia vapors, is positively driven by a driving roller 32 and is guided by a plurality of tensioning and guide rollers 33, 34, 35, and 36 so that it grips and is maintained in contact with material to be developed along substantially the entire extent of the lower wall 37 of the vaporizing chamber or tank 28. While the same is not wholly necessary and forms no essential part of this invention, a fine mesh link belt 33 driven by roller 29 and guided by a plurality of other rollers 4B, 4!, and 42 serves to space the sensitized layer from the surface of the tank and thereby to diffuse the ammonia vapor and assist in conveying the material to be developed past the developing zone in a manner described in U. S.

Patent 2,515,834, issued July 11, 1950. If the mesh belt 38 is not employed, then the sealing sleeve 31 maintains the sensitized material in direct contact with the smooth surface 3'! of the tank andexerts sufficient pressure upwardly toward this surface to maintain the sensitized layer fiat against the adjacent portion of the tank and seals the vapors within the tank except as they are permitted to pass through a plurality of apertures to reach the coated surface of the sensitized layer as it is moved past the developing zone.

The channel formed between the guide memhers 23 and 24 continues on up to a point where the sensitized sheet is caused to be gripped'between the sealing sleeve 31 and-the surface of the tank side 37 or the mesh link belt -33, as the case may be. To effect this, the member 24 curves about the center of the drive roller 32 as indicated at 43.

After the sheet has been subjected to the action of the ammonia vapors, it is projected upwardly by the action of the sealing sleeve as. the

iii;

'6 same passes up over guide roller 36 and, depending upon the position of a deflector M, will be discharged forwardly into a receiving tray 45 or to the rear of the machine in a manner not necessarily to be described here since this portion of the mechanism forms the subject matter of a separate case.

The vaporizing chamber or tank 28 is of considerable horizontal extent, but does not occupy a great amount of vertical space, so the discharge of the material to the tray 45 occurs at a relatively low level. Accordingly, the machine need occupy very little vertical space compared to other machines adapted to perform both the printing and deveoping functions as a continuous process and wherein the machine is adapted to considerable speed so that the sensitized material must be maintained within the influence of the developing vapors for a comparatively great period of time.

Since the vapors in the tank 28 cannot always be maintained and it is not desired that they be maintained absolutely dry, provision is made for collecting and discharging any condensation which may be experienced, especially such as that which occurs during starting up of the machine when all parts are cold, or when accidenttally or otherwise too great an amount of ammonia is fed, or for other reasons. It is a known fact that the developing action of the more moist vapors is considerably faster than that of substantialy dry vapors. Thus, the fact that the vapors at substantially the lowest part of the chamber are used for contacting the sensitized layer makes possible greater speed of development than has been found practicable where the reverse or top side or upwardly directed side of the tank has been perforated and employed as a developing surface.

To prevent condensation from reaching the sealing sleeve or from reaching the sensitized sheet, the lower side 3'! of the tank is formed as illustrated in Fig. 2. The perforations 46 are extruded or otherwise ormed so that an inwardly turned lip or flange 41 surrounds each perforation thereby to leave a space 48 between the perforations which constitutes a reservoir by which such sma l amount of condensation as mav be inevitable is returned to the lowest portion of the tank (at the extreme lower righthand side, Fig. 1) which is not perforated, but from which the condensation and excess ammonia are drained. 7

These perforations 45 are preferably formed as closely together as practicab e and may be staggered as is the usual practice. The fact that the lips or flanges 4! arepresent adds slightly to the cost of prod ct on but results in a more rigid and stronger perforated wall for the tank. In Fig. 2, the sensitized sheet T is shown in direct contact with the tank surface 3! although if the mesh belt 38 were employed, that would intervene so that there would be no direct contact between the coated surface of the sheet T and adja ent stationary parts. The fact that the perforations are curved inwardly as shown renders the outer surface of the wall 37 less likely to scrape or damage the surface ,of the sheet T and does not necessitate a special rounding or smoothing of the perforation edge as may be necessary when the parts are constructed as has been the practice according to the prior art.

The lips or flanges 4'! are preferably an integral part of the tank wall as shown and as just de scribed. However, .it-may be desirable in some instances to form them as inserts in which they constitute a separate part pressed into apertures formed in the tank wall to form a liquid-tight joint. The inclination of thegwall 31 may be varied within limits and, in fact, may be nearly horizontal or may extend upwardly at a more vertical angle than that illustrated so long as the general principles of the invention are applied. The distinguishing characteristics are evident in the fact that the developing surface or perforated portion of the tank through which the vapors escape to reach the, sensitized sheet is directed in a downward rather than an upward direction and the vapors asthey move from the tank through the perforations to reach the sensitized layer have a definite downward component.

While the extent and inclination of the wall '31 may be varied through reasonable limits, the

vapors which are brought into active contact with the sensitized sheets are always those lying adjacent the lower part of the tank and, therefore, contain the largest amount of moisture. That assures the greatest speed of development consistent with the general condition of the vapors. Furthermore, the general arrangement of parts as hereinabove described contributes to the positive control of both the sensitized sheet and the original with a minimum of suction being applied to the latter. The fact that the material throughout its entire extent of travel is directed in a direction more horizontal than vertical as compared to machines of the prior art makes possible a much more advantageous use of the space within the machine casing and provides for a machine of marked capacity, but much smaller than has been considered practical heretofore. Since printing and developing machines of this type are generally purchased and added to a department already established and in which there is frequently little space for additional equipment, reduction in overall dimensions, especially height of the apparatus, is important.

While one embodiment of the invention has been disclosed, it is to be understood that the inventive concept may be carried out in a number of ways. This application is, therefore, not to be limited to the precise details described, but is intended to cover all variations and modifications thereof falling within the spirit of the invention and the scope of the claims.

I claim:

1. In a dry developing machine of the type described, the combination of a vaporizing chamber; developer vaporizing means within said chamber and a sealing sleeve movable along and in contact with one surface of said chamber for retaining vapo'rs within the chamber and for advancing sensitized material to be developed past said chamber, said chamber having one wall thereof perforated for permitting the passage of developing vapors to the sensitized material and comprising the lower side of the chamber, said perforated chamber wall having the perforations therein provided with upwardly turned circumferential flanges thereby to define a reservoir between the perforations for receiving the .con-

densate of said vapors.

2. In a dry developing machine of the type described, the combination of a vaporizing chamber, developer vaporizing means within said chamber and a sealing sleeve movable along and in contact with one surface of said chamber for retaining vapors within the chamber and for advancing sensitized material to be developed past said chamber, said chamber having one wall thereof perforated for permitting the passage of developing vapors to the sensitized material, said wall comprising the lowermost side of the chamber and being inclined slightly upwardly from the horizontal, said perforated chamber wall having inwardly extruded perforations, the extruded flanges formed thereby being upwardly directed thereby to define a reservoir between the perforations for receiving and directing the condensate of said vapors to a lowermost point in said tank from which it is drained.

3. In a dry developing machine, the combination of a vaporizing chamber having a perforated wall, means in said chamber for receiving, heating and vaporizing a developer liquid, a sealin sleeve and guiding and driving means for said sleeve for maintaining it in contact with a sensitized layer and for retaining said layer incontact with a perforated wall of the chamber and moving it along said wall, said perforated wall being inclined slightly upwardly from the horizontal from a lowermost portion of the tank into which condensed vapors and excess developer liquid are drained, said wall further havingits perforations extruded inwardly of the chamber thereby to define a reservoir for receiving the condensate of said vapors and for directing this condensate to the said lowermost portion of the tank from which it is drained.

4. In a developing machine of the type described an aqueous ammonia developer vaporizing chamber comprising a closed tank, a wall for said tank having a plurality of perforations for the escape of ammonia vapors, said tank being located in said machine with the perforated wall facing downwardly and in a substantially horizontal position, whereby predominantly water saturated ammonia vapors reach the sensitized material in contact with said wall, and means comprising vertically extending barriers on the inside surface of said wall between each of said perforations and providing a means between said barriers for collecting the condensate of the developer vapors, and by-passing it past said perforations out of contact with said material.

5. In a developing machine of the type described, an aqueous ammonia developer vaporizing chamber comprising a closed tank, a wall for said tank having a plurality of perforations for the escape of ammonia vapors, said tank being located in said machine with the perforated wall facing downwardly and in a substantially horizontal position, whereby predominantly water saturated ammonia vapors reach the sensitized material in contact with said wall, said perforations having raised edges for collecting and bypassing the condensate of the vapors.

FREDERICK OTTO TRUMP.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

